Needle-bar throwout mechanism for tufting machine



Aug. 12, 1969 w. M. GAINES NEEDLE-BAR THROWOUT MECHANISM FOR A TUF'IINGMACHINE Filed Feb. 19, 1968 2 Sheets-Sheet 1 4 m NW w WM m .w W

ATWORNEY WITNESS: 6 0b Jolwgg Aug. 12, 1969 W.M. GAINES NEEDLE-BARTHROWOUT MECHANISM FOR A TUFTIN G MACHINE Filed Feb. 19, 1968 2 SheetS'Sheet'Z INVENTQR. wlllmm M. Games ORN EX United States Patent 3,460,499NEEDLE-BAR THROWOUT MECHANISM FOR TUFTING MACHINE William M. Gaines,Lafayette, Ga., assignor to The Singer Company, New York, N.Y., acorporation of New ersey Filed Feb. 19, 1968, Ser. No. 706,248 Int. Cl.Dh 69/22 US. Cl. 112-221 6 Claims ABSTRACT OF THE DISCLOSURE An operatoractuated mechanism for a tufting machine for disengaging the needle-barfrom the needle-bar driving collar, including latch fingers carried onthe needle bar for providing a driving connection between the needlebardriving collar and the needle-bar, and an unlatching member utilized tooperate the latch fingers to disengage the needle-bar from theneedle-bar driving collar. Mechanism including a spring biased brakingmember is utilized to hold the needle-bar in a raised position after ithas been disengaged from the needle-bar driving collar.

Background of the invention In some of the prior art tufting machinessuch as that disclosed in the United States Patent No. 2,314,339, Mar.23, 1943, R. H. Bradwell, operator influenced mechanism is included fordisconnecting the needle-bar from its drive means. The Bradwell patentalso includes mechanism for holding the needle-bar in a raised positionafter it has been disconnected from its drive elements. In the Bradwellpatent, there is disclosed a pivotal connecting arm carried by theneedle-bar one end of which operatively connects the needle-bar to thedrive means. In addition, the Bradwell mechanism includes a manuallyoperable latch arm pivotally mounted in the tufting machine head andadapted to pivot the connecting arm to disengage the needle-bar from itsdrive means and hold the needle-bar in a raised position.

In the Bradwell mechanism when the needle-bar reconnecting means isactuated it is possible for the needlebar to drift downwardly before thedrive means is reengaged with the needle-bar. When this occurs the drivemeans and the needle-bar are reengaged at a point in the endwisereciprocatory cycle of the drive means when the drive means is moving ata relatively high speed. The resultant jarring impact as the needle-barand the drive means engage at such a relatively high speed could resultin damage to the pertinent machine parts and in addition results in aloud annoying clatter. Another drawback disclosed in the Bradwell patentis that the operative connection between the needle-bar and theneedle-bar drive means consists of only one arm which makes theconnection on one side only of the needle-bar thereby exerting a sidethrust during normal operation on the needle-bar which causes abnormalneedle-bar bearing wear.

Summary of the invention ing the force applied on the needle-bar. Inaddition, the

operative connection between the needle-bar and the driving collarincludes two oppositely disposed pivotally mounted fingers carried bythe needle-bar.

The described embodiment of the present invention avoids the drawbacksof the prior art mechanism briefly outlined above by utilizing resilientmeans for gradually releasing the braking force applied to theneedle-bar thereby preventing the needle-bar from drifting downwardlybefore the needle-bar is reengaged with the driving means, therebyobviating any jarring shocks to the pertinent machine elements and theattendant annoying clatter. In addition, the provision of the twooppositely disposed fingers connecting the needle-bar to the needlebardriving collar obviates the side thrust exerted on the needle-bar duringnormal operation as is the case in the Bradwell mechanism.

It is an object of this invention to provide an improved mechanism tordisengaging the needle'bar from the needle-bar driving collar in anymachine having such needle-bar mechanism.

It is another object of this invention to provide an improved mechanismfor holding the needle-bar in a raised position after it has beendisengaged from the needle-bar driving collar.

Having in mind the above and other objects that will be evident from anunderstanding of this disclosure, the invention comprises the devices,combinations and arrangements of parts as illustrated in the presentlypreferred embodiment of the invention which is hereinafter set forth insuch detail as to enable those skilled in the art readily to understandthe function, operation, construction and advantages of it when read inconjunction with the accompanying drawings.

Brief description of the drawings FIG. 1 is a side elevational view ofa. tufting machine embodying the present invention.

FIG. 2 is a skeletonized perspective view of elements of the presentinvention positioned in the head of the tufting machine shown in FIG. 1.

FIG. 3 is an elevational head-end view of the tufting machine shown inFIG. 1.

FIG. 4 is an enlarged view of the section taken substantially along line4--4 of FIG. 3.

Description of the preferred embodiment With reference to the drawingsthere is illustrated a single needle tufting machine 10 having a frameformed with a bed 12 from one end of which rises a standard 14 thatsupports an arm 16 terminating in a head 18 above the bed 12. A rotaryarm shaft 20 is journaled longitudinally of the arm 16 and has securedto its extremity within the head 18 a crank 22 pivotally connected to adriving link 24 via a pin 26. The lower extremity of the driving link 24is formed into a hollow cylinder 28 within which is pivotally mounted acylindrical stud 30 connected to a block 32 formed with a cylindricalhole 34 which receives a vertically mounted needle-bar 36 in slidingengagement therewith. The needle-bar 36 has a uniform cross sectionalconfiguration for a continuous portion thereof in length exceeding theamplitude of needle-bar reciprocation. The needle-bar 36 supports aneedle 38 and is journaled for endwise reciprocation in a bearing 40mounted in the bottom section of the head 18 and a bearing sleeve 42slidably mounted in an aperture in the roof 43 of the head 18. Thesleeve 42 is held against turning movement about its axis by a screw 45which contacts a slabbed surface (not shown) on the bearing sleeve 42.Also, mounted vertically in the head 18 for endwise movement is apresser-bar 44 that supports a presser-foot 46 on its lower extremity.It is here noted that the present invention could also be embodied in asewing machine that utilizes an endwise reciprocable needle-bar.

Mounted in the bed 12 of the machine beneath the head 18 are the usualthroat plate 48, feed dog 50, looper 52 and a loop cutting blade 54. Thedrive mechanism for the feed dog, looper, blade and needle-bar is timedso that the needle and feed mechanism cooperate to provide a line of cutloops in the backing material, in the usual manner.

Extending through the bed 12 and upwardly adjacent the standard 14 is aconnecting rod 56 the lower end of which may be operatively connected toa foot treadle or knee lift of any other means designed to impartendwise movement to the connecting rod. The upper end of the connectingrod is pivotally connected to one extremity of a lever 58 in turnpivotally mounted intermediate its ends on the shank of a shoulder screw60 secured to the arm 16. To the other extremity of the lever 58 thereis secured a pin 62 which protrudes through a slot 64 formed in theupper extremity of a vertically disposed bar 66 and through a circularopening 68 formed in the lower extremity of a Vertically mounted link70. The lower extremity of the vertically disposed bar 66 is secured toa leverage block 72 formed with a hollow cylindrical section 74 whichslidably receives the presserbar 44. Above the hollow cylindricalsection 74 there is secured to the presser-bar an apertured block 76 andmounted on the presser-bar 44 between the block 76 and the ceiling ofthe upper section of the head 18 is a coil spring 78 which exerts adownwardly directed pressure on the block 76. The pressure exerted bythe spring is capable of being adjusted by a hollow thumb 80 threadedinto the top 43 of the head 18. A hand-operated presserfoot lift lever83 is pivotally mounted on the head 18 for operative engagement with theleverage block 72, in the usual manner.

The upper section of the vertically mounted link 70 is pivotallyconnected to one extremity of a horizontally disposed rock lever 82formed with a vertical, centrally located, elongated aperture 84 and ahorizontal, cylindrically shaped aperture 86 extending through the lever82 midway between the lever ends and transversely of the length of theaperture 84. The aperture 84 receives an apertured stud 88 that extendsupwardly from a rocking block 90, with which it is integrally formed.The rocking block 90 is pivotally mounted on a pin 92 secured to thehead 18 The stud 88 is pivotally connected to the rock lever 82 by a pin94 received by an aperture in the stud 88 and press fit into the hole 86in the rock lever 82. The other extremity of the rock lever 82 ispivotally connected by a pin 91 to a U-shaped connecting bar 93 formedwith a pair of parallel legs 96. Depending from the roof 43 of the head18 is a vertically adjustable stud 95 mounted in an aperture in the roof43 and formed at its lower end with a disc 97 that extends into thevertical path of the bar 93 thereby to place a lower limit on thevertical path along which the bar 93 may move.

The bearing sleeve 42 is formed in its upper section with a verticalslot '98, the outer surface of the midsection of the sleeve beingthreaded at 100 for a reason set forth below. An apertured yarn orthread guide finger 99 secured to the needle-bar 36 is received by thevertical slot 98. The sleeve 42 includes a lower extremity 102 formedwith a plurality of spaced vertical slots 104 that define a plurality oftangs 105. The tangs 105 each includes a shank section 106 having athickness less than that of the section of the sleeve 42 above the lowerextremity 102. The lower end of the shank for each tang curves outwardlyto form a lip 108. The lip 108 is thicker than any of the other sectionsof the sleeve and takes the shape of one of the halves of a frustrumwhich has been sectioned along its vertical axis. Slidably mounted onthe sleeve 42 is a collar 110 formed in the inner surface of its lowerextremity with a conical recess 112 that extends inwardly from thebottom of the collar and is adapted to engage the outer surface of thelip 108, as explained below. Also mounted on the sleeve 42, above thecollar 110, is a coil spring 114 the lower end of which engages theupper end of the collar 110. Also mounted on the sleeve 42 is acylindrical unlatching block 116 having a reduced upper section 118whose outer surface is formed with two oppositely disposed grooves 120which in cross section are shaped rectangularly. The grooves 120 areformed to receive the spaced parallel legs 96 of the U-shaped connectingbar in sliding engagement therewith. The unlatching block 116 isprovided with an aperture 122 formed to receive the sleeve 42 and aconical recess 124 in the wall of the aperture 122 which extendsinwardly from the bottom of the unlatching block. The aperture 122 iscountersunk at 126 to receive the sleeve 42, spring 114 and collar 110,as best understood by viewing FIGS. 2 and 4. The sleeve 42, collar 110,spring 114 and the unlatching block 116 are held together as a unit by anut 128. The nut 128 is mounted on the bearing sleeve 42 above the head18, and when it is turned to threadedly engage the threaded mid sectionit serves to pull the shank 106, collar 110, spring 114 and block 116upwardly toward the top 43 af the head 18. As the nut 128 is rotatedclockwise, as viewed from above, the sleeve 42 is pulled upwardly,thereby forcing the lip 108 into contact with the conical recess 112 inthe collar 110, which collar contacts the coil spring 114 and forces itupwardly against an inner stop ledge 130 formed in the wall of theaperture 122 of the unlatching block 116, thereby to move the blockupwardly and bring the elements within the block together as a unit.

Secured to the needle-bar 36 intermediate its ends is a latching block132 formed with a cylindrical aperture 134 which receives the needle-bar36. The latching block 132 is formed from two rectangular blocks 136 and138, the smaller block 138 having for-med therein a threaded aperturethat receives a screw 140. The latching block 132 is formed with a slit142 whose sides may be moved toward or away from each other by adjustingthe screw 140, thereby to tighten or loosen the block on the needlebar.Into each of two oppositely disposed sides 144 of the latching block 132there is cut a vertical slot 146 each of which receives a latch finger148. Each latch finger 148 is pivotally mounted intermediate its ends ona pin 150 mounted in the latching block. Each latch finger 148 is formedwith an upper unlatching end section 152 formed with an outer surface154 that bends inwardly towards the needle-bar and is adapted to engagethe conical recess 124 in the unlatching block 116 when the unlatchingblock is actuated. Each latch finger 148 is also formed at its lowerextremity into a hook 156 having a horizontal lip 158 that extendsinwardly towards the needle-bar 36. The latch fingers 148 are biased bya substantially M-shaped spring 160 mounted on the large block 136 andconnected at each end extremity of the spring to a respective one of thelatch fingers so that the lower extremity of each latch finger ispivoted inwardly towards the needle-bar 36. Extending upwardly from andsecured to the block 32 is a latch collar 162 formed with a circularflange 164 under which the horizontal lip 158 of each of the latchfingers may slip to entrain the needle-bar with the block 32, asexplained below.

Turning now to the operation of the mechanisms described above, as theneedle 38 moves downwardly it carries thread (not shown) down throughwork material (not shown) being moved over the throat plate 48 by thefeed dog 50, whereupon the looper 52 intercepts the thread thereby toform a loop of the thread on the looper as the needle moves back upthrough the work material. The cutter 54 and looper 52 move in such amanner as to cause the severance of each loop of thread as it is formedon the looper thereby to provide the line of severed tufts desired. Whenthe operator wishes to start a new line of tufts or for any other reasonwishes to stop the reciprocation of the needle-bar but continue theoperation of the looper and cutter thereby to sever any accumulatedloops on the looper the operator need merely, according to thearrangement of the mechanism of the present invention, actuate thetreadle or knee lift that is connected to the connecting rod 56. Whenthis occurs the rod 56 is pulled downwardly thereby pivoting the lever58 on the shoulder screw 60 and raising the pin 62 at the end of thelever 58 upwardly. The upward movement of the pin 62 pulls thepresser-foot 46 upwardly against the bias of the spring 78 and alsopushes the link 70 upwardly. Upward movement of the link 70 pivots therock lever 82 thereby to push the U-shaped connecting bar 93 downwardly.As the bar 93 moves downwardly the legs 96, captured by the grooves 120,force the cylindrical unlatching block 116 downwardly against the biasexerted by the coil spring 114. When the block 116 reaches apredetermined point in its downward movement it is in position to beengaged by the latch fingers 148. As the block 116 is moved downwardlythe needle-bar carrying the latching block 132 continues to reciprocateuntil the upper unlatching end sections 152 are brought into engagementwith the wall of the conical recess 124 thereby to urge the sections 152inwardly. The unlatching occurs when the needle-bar is at or very cloesto the top of its run at which point the needle-bar is stopped or movingvery slowly. Thus, the fingers 148 are pivoted so that the hook end 156of the fingers moves outwardly and the lip 158 of the fingers slides outfrom beneath the circular flange 164 on the latch collar 162. FIG. 4shows the fingers in both the latched (dot-dash outline) and theunlatched (solid outline) positions. Because the drive mechanism of thetufting machine has not been disengaged by the actuation of theunlatching block 116 the crank 22 continues to move the driving block 32and the latch collar 162 up and down over the surface of the needle-bar44, while the needle-bar remains in a raised position, as explainedbelow. In addition, the drive mechanism for the feed, looper and cuttercontinues to operate thereby to sever any loops of thread remaining onthe looper, without forming any additional loops. Since the presser-footis raised at this point the operator may move the work material in anydirection over the bed of the machine to change the position of the workmaterial relatively to the needle so that the operator may thereafterchange the direction of the seam or start a new seam.

Turning now to the operation of the mechanism utilized to hold theneedle-bar in a raised position, as can be seen more clearly in FIGS. 2and 4 as the unlatching block 116 is pushed downwardly pressure isapplied gradually through the coil spring 114 to the collar 110 which inturn gradually forces the tangs 105 inwardly into engagement with theneedle-bar 36. The resiliency of the coil spring 114 acts to preventundesirable wear on the needle-bar as it is being reciprocated afterpressure has been applied to the tangs 105, forcing them inwardly intocontact with the needle-bar, and before the latch fingers 148 areactuated. After the latch fingers 148 have been actuated and theneedle-bar disengaged from the driving block 32 at the top of theneedle-bar run the continued application of pressure on the needle-barthrough the block 116, spring 114, collar 110 and the tangs 105 servesto hold the needle-bar in its raised position against any tendency forthe needle-bar to drift downwardly.

When the operator again actuates the treadle or knee lift in order toonce again entrain the needle-bar with its drive elements the unlatchingblock 116 is moved upwardly to its raised position thereby releasing thelatch fingers 148 which pivot back to their original position. Thedriving block 32 meanwhile continues to be driven up and down along theneedle-bar 36. When the flanges 164 is brought into engagement with thelower extremity of the latch fingers 148 the latch fingers are onceagain operatively connected to the latch collar 162. The presentinvention provides that the reengagement off the needle-bar, through thelatch fingers, with the driving block 32 takes place at or near the topof the needle-bar run when the driving block is moving very slowly.Thus, the impact of the parts as they reengage is very slight preventingdamage to the parts and making the engagement practically noiseless. Thereengagement at or near the top of the needle-bar run is made possibleby the provision of the coil spring 114. Thus, when the block 116 islifted the needle-bar is not released immediately from the grip of thetangs because the spring 114 expands gradually after it is released fromthe compressing force of the block 116 thereby to release the pressureon the tangs 105 gradually so that the needle bar will not beimmediately free to drift downward. The delay provided by the spring 114is suflicient to prevent the needle-bar from drifting downwardly beforethe driving block 132 has time to reach the top of its vertical movementno matter where in the cycle of endwise reciprocation the driving block132 may be when the block is lifted.

Having thus set forth the nature of this invention, what is claimedherein is:

1. A needle-bar disengaging apparatus for a machine of the classdescribed having a frame, a needle-bar carried by said frame for endwisereciprocation relatively thereto, a needlebar reciprocating meanscarried in said frame, said needle-bar having a uniform cross sectionalconfiguration for a continuous portion thereof in length exceeding theamplitude of needle-bar reciprocation, said needle-bar disengagingapparatus comprising saparable interengaging means on said needle-barand on said needle-bar disengaging apparatus comprising separableelement shiftably supported on said needle-bar and having an operativeposition for separating said interengaging means, means shiftablysupported on said frame for movement into and out of effective positionin the path of said disengaging element at a predetermined position ofreciprocation of said needle-bar to urge said disengaging element intosaid operative position, selectively effective friction brake meanscarried on said frame and engageablable with said needle-bar portion ofuniform cross sectional configuration, and means responsive to movementof said means shiftably supported on said frame for rendering saidfriction brake means eifective at least until said disengaging elementis released by said means shiftably supported on said frame and saidinterengaging means are reengaged.

'2. A needle-bar disengaging apparatus as set forth in claim 1 whereinsaid means for rendering said friction brake means effective includes acoil spring operatively connecting said friction brake means to saidmeans shiftably supported on said frame.

3. A needle-bar disengaging apparatus as set forth in claim 1 whereinsaid means shiftably supported on said frame includes a control blockand said selectively effective friction brake means includes a resilientmember operably acted upon by said control block selectively to bringsaid resilient member into engagement with said needle-bar.

4. A needle-bar disengaging apparatus as set forth in claim 3 includinga spring operatively connected between said control block and saidresilient member.

5. A needle-bar disengaging apparatus as set forth in claim 1 in whichsaid separable interengaging means includes a pair of disengagingelements pivotally supported relatively to said needle-bar atdiametrically opposite sides thereof, said disengaging elements eachformed at one extremity with an inturned hook and at the oppositeextremity with an operating arm and a collar connected to saidneedle-bar reciprocating means, said collar having formed thereon aflange, said collar being endwise slidable on said needle-bar and saidannular flange being complemental to the inturned hooks on saiddisengaging ele- 7 ments, and in which said means shiftably supported onsaid frame includes a control block supported on said frame for movementcoaxially of said needle-bar, said control block being formed withcamming surfaces shiftable into the paths of said operating arms of saidd'isengaging elements.

6. A needle-bar disengaging apparatus as set forth in claim 5 in whichsaid friction brake means comprises a bearing sleeve for saidneedle-bar, a resilient member formed on said bearing sleeve, and meansshiftable in response to movement of said control block to bring saidresilient member into engagement with said needle-bar.

8 References Cited UNITED STATES PATENTS 3/ 1943 Bradwell 112-221 XR5/1943 Cobble et al 112221 XR FOREIGN PATENTS 12/1966 Germany.

US. Cl. X.R.

